Wireless devices can be monitored for a variety of applications involving vehicles, pedestrians, public transportation and other contexts. The case of traffic monitoring is illustrative. Conventionally, traffic information was obtained by using human observers in vehicles or aircraft, or by using cameras distributed at various locations across a monitored portion of the roadway network. The resulting traffic information could then be reported to motorists on the roadway network (or soon to be on the roadway network) via radio, television, telephone or other devices or could be reported to government officials or others. This traffic information could then be used by the motorists, for example, to select routes, to determine approximate travel times, to allocate resources, to manage traffic (e.g., by setting or changing traffic light cycle times/durations or otherwise for planning purposes. While useful, this information was not always timely, complete, or readily available to motorists and other interested parties.
More recently, automated or semi-automated systems have been proposed for monitoring traffic conditions. These systems detect vehicles on roadways and employ a processor to determine traffic information based on the detected vehicles. Such systems include systems that detect vehicles based on Bluetooth™ technology. Bluetooth™ technology is typically used to replace wireline connections between master-slave device pairings of a wireless personal area network, e.g., between a mobile phone and a wireless headset or between a mobile phone and a Bluetooth™ enabled car radio. Because of the personal area network nature of these devices, the associated radio transceivers generally have a short communications range, often on the order of meters or tens of meters. Moreover, because these devices are intended for use in a dedicated master-slave network context, communication between devices may be sporadic (e.g., on an as-needed basis) and generally do not include, for example, probe requests searching for LAN or WAN access points and are not generally associated with received signal strength indication (RSSI) values.